tmux new-session -d -s i-want-full-core
tmux new-window -t i-want-full-core:1 
tmux select-window -t i-want-full-core
tmux split-window -p 75  
tmux split-window -p 75
tmux split-window -p 50
tmux setw synchronize-panes on
tmux attach-session -t i-want-full-core
